Chronically high stress hormone levels dysregulate sperm long noncoding RNAs and their embryonic microinjection alters development and affective behaviours.

Previous studies on paternal epigenetic inheritance have shown that sperm RNAs play a role in this type of inheritance. The microinjection of sperm small noncoding RNAs into fertilised mouse oocytes induces reprogramming of the early embryo, which is thought to be responsible for the differences observed in adult phenotype. While sperm long noncoding RNAs (lncRNAs) have also been investigated in a previous study, their microinjection into fertilised oocytes did not yield conclusive results regarding their role in modulating brain development and adult behavioural phenotypes. Therefore, in the current study we sought to investigate this further. We used our previously established paternal corticosterone (stress hormone) model to assess sperm lncRNA expression using CaptureSeq, a sequencing technique that is more sensitive than the ones used in other studies in the field. Paternal corticosterone exposure led to dysregulation of sperm long noncoding RNA expression, which encompassed lncRNAs, circular RNAs and transposable element transcripts. Although they have limited functional annotation, bioinformatic approaches indicated the potential of these lncRNAs in regulating brain development and function. We then separated and isolated the sperm lncRNAs and performed microinjections into fertilised oocytes, to generate embryos with modulated lncRNA populations. We observed that the resulting adult offspring had lower body weight and altered anxiety and affective behavioural responses, demonstrating roles for lncRNAs in modulating development and brain function. This study provides novel insights into the roles of lncRNAs in epigenetic inheritance, including impacts on brain development and behaviours of relevance to affective disorders.

Experience-dependent neural plasticity, learning, and memory in the era of epitranscriptomics.

In this short review, we highlight recent findings in the emerging field of epitranscriptomic mechanisms and discuss their potential role in neural plasticity, learning and memory. These include the influence of RNA modifications on activity-induced RNA structure states, RNA editing and RNA localization, and how qualitative state changes in RNA increase the functional diversity and information-carrying capacity of RNA molecules. We predict that RNA modifications may be just as important for synaptic plasticity and memory as quantitative changes in transcript and protein abundance, but with the added advantage of not being required to signal back to the nucleus, and therefore better suited to be coordinated with the temporal dynamics of learning.

Polymer gel dosimetry for measuring the dose near thin high-Z materials irradiated with high energy photon beams.

PURPOSE: To investigate the feasibility of three-dimensional (3D) dose measurements near thin high-Z materials placed in a water-like medium by using a polymer gel dosimeter (PGD) when the medium was irradiated with high energy photon beams. METHODS: PGD is potentially a useful tool for this application because it can record the dose around a small object made of a high-Z material in a continuous 3D medium. In this study, the authors manufactured a methacrylic acid-based normoxic PGD, nMAG. Two 0.5 mm thick lead foils (1 × 1 cm) were placed in foil supports with 0.7 cm separation in a 1000 ml polystyrene container filled with nMAG. The authors used two foil configurations, i.e., orthogonal and parallel. In the orthogonal configuration, two foils were placed in the direction orthogonal to the beam axis. The parallel configuration had two foils arranged in parallel to the beam axis. The phantom was irradiated with an 18 MV photon beam of 5 × 5 cm field size. It was imaged with a three-Tesla (3 T) magnetic resonance imaging (MRI) scanned using the Car-Purcell-Meiboom-Gill pulse sequence. The spin-spin relaxation time (R2) to-dose calibration data were obtained by using small vials filled with nMAG and exposing to known doses. The DOSXYZnrc Monte Carlo (MC) code was used to get the expected dose distributions. More than 35 × 106 of histories were simulated so that the average error was less than 1%. An in-house matlab-based software was used to obtain the dose distributions from the measured R2 data as well as to compare the measurements and the MC predictions. The dose change due to the presence of the foils was studied by comparing the dose distributions with and without foils (or the reference). RESULTS: For the orthogonal configuration, the measured dose along the beam axis showed an increase in the upstream side of the first foil, between the foils, and on the downstream side of the second foil. The range of increased dose area was 1.1 cm in the upstream of the first foil. However, in the downstream of the second foil, it was 0.2 cm, beyond which the dose fell below the reference dose by 10%. The dose profile between the foils showed a well-like shape with the minimum dose still larger than the reference dose by 1.8%. The minimum dose point was closer to the first foil than to the second foil. For the parallel configuration, the dose between foils was the largest at the center. The increased dose area opposite to the gap between foils extended outward to 1 cm. The spatial dose distributions of PGD and MC showed the same geometrical patterns except for the points inside the foils for both orthogonal and parallel foil arrangements. CONCLUSIONS: The authors demonstrated that the nMAG PGD with MRI could be used to measure the 3D dosimetric structures at the mm-scale in the vicinity of the foil. The current study provided more accurate 3D spatial dose distribution than the previous studies. Furthermore, the measurements were validated by the MC simulation.

Crystal structure of an archaebacterial DNA polymerase.

BACKGROUND: Members of the Pol II family of DNA polymerases are responsible for chromosomal replication in eukaryotes, and carry out highly processive DNA replication when attached to ring-shaped processivity clamps. The sequences of Pol II polymerases are distinct from those of members of the well-studied Pol I family of DNA polymerases. The DNA polymerase from the archaebacterium Desulfurococcus strain Tok (D. Tok Pol) is a member of the Pol II family that retains catalytic activity at elevated temperatures. RESULTS: The crystal structure of D. Tok Pol has been determined at 2.4 A resolution. The architecture of this Pol II type DNA polymerase resembles that of the DNA polymerase from the bacteriophage RB69, with which it shares less than approximately 20% sequence identity. As in RB69, the central catalytic region of the DNA polymerase is located within the 'palm' subdomain and is strikingly similar in structure to the corresponding regions of Pol I type DNA polymerases. The structural scaffold that surrounds the catalytic core in D. Tok Pol is unrelated in structure to that of Pol I type polymerases. The 3'-5' proofreading exonuclease domain of D. Tok Pol resembles the corresponding domains of RB69 Pol and Pol I type DNA polymerases. The exonuclease domain in D. Tok Pol is located in the same position relative to the polymerase domain as seen in RB69, and on the opposite side of the palm subdomain compared to its location in Pol I type polymerases. The N-terminal domain of D. Tok Pol has structural similarity to RNA-binding domains. Sequence alignments suggest that this domain is conserved in the eukaryotic DNA polymerases delta and epsilon. CONCLUSIONS: The structure of D. Tok Pol confirms that the modes of binding of the template and extrusion of newly synthesized duplex DNA are likely to be similar in both Pol II and Pol I type DNA polymerases. However, the mechanism by which the newly synthesized product transits in and out of the proofreading exonuclease domain has to be quite different. The discovery of a domain that seems to be an RNA-binding module raises the possibility that Pol II family members interact with RNA.

Reconstructing phylogeny with and without temporal data.

Conventional cladistic methods of inferring evolutionary relationships exclude temporal data from the initial search for optimal hypotheses, but stratocladistics includes such data. A comparison of the ability of these methods to recover known, simulated evolutionary histories given the same, evolved character data shows that stratocladistics recovers the true phylogeny in over twice as many cases as cladistics (42 versus 18 percent). The comparison involved 550 unique taxon-by-character matrices, representing 15 evolutionary models and fossil records ranging from 100 to 10 percent complete.

Crystallographic analysis of the recognition of a nuclear localization signal by the nuclear import factor karyopherin alpha.

Selective nuclear import is mediated by nuclear localization signals (NLSs) and cognate transport factors known as karyopherins or importins. Karyopherin alpha recognizes "classical" monopartite and bipartite NLSs. We report the crystal structure of a 50 kDa fragment of the 60 kDa yeast karyopherin alpha, in the absence and presence of a monopartite NLS peptide at 2.2 A and 2.8 A resolution, respectively. The structure shows a tandem array of ten armadillo repeats, organized in a right-handed superhelix of helices. Binding of the NLS peptide occurs at two sites within a helical surface groove that is lined by conserved residues. The structure reveals the determinants of NLS specificity and suggests a model for the recognition of bipartite NLSs.

Sickness absence following a campaign of vaccination against influenza in the workplace.

This study was designed as a retrospective cohort study of those employees vaccinated against influenza vs. unvaccinated employees in a service company. The objective was to investigate whether vaccinating employees against influenza in an occupational setting was of any benefit. There were 2,557 persons entered in the study who were in continuous employment between 1 October 1990 and 31 March 1992 of which 23.5% (601) were vaccinated. The study was carried out at First Data Resources Limited in Basildon, Essex UK. The main outcome measure was self-reported influenza sickness lasting four or more days and reduction in sickness absence due to vaccination against influenza. The results were surprising. In the vaccinated members of staff, influenza illness was halved, Relative Risk = 0.46, 95% confidence limits (0.27 < RR < 0.76). The conclusions were that the study showed a significant decrease in sickness absence due to influenza illness, as a result of an active vaccination campaign carried out amongst otherwise healthy individuals in the occupational health environment. This is the first study of this nature in the UK to show statistically significant evidence of benefit from vaccinating healthy employees. It lends support to immunization against influenza in the workplace.

Physical and functional interactions between p53 and cell cycle co-operating transcription factors, E2F1 and DP1.

One way in which wild-type p53 is able to regulate cell cycle progression is thought to be via the induction of its downstream target gene Waf1/CIP1, thus indirectly regulating the transcriptional activity of E2F. The E2F transcription factors are known to be key effectors of the cell cycle. We report here that there is a physical and functional interaction between p53 and two of the components of the E2F transcription factors, E2F1 and DP1. The expression of wild-type p53 can inhibit the transcriptional activity of E2F, and the expression of both E2F1 and DP1 can also downregulate p53-dependent transcription. The transcriptional activity of p53 is known to be inhibited by the direct binding of mdm2, but we demonstrate here that both E2F1 and DP1 can inhibit p53 transcriptional activity independently of mdm2. Detailed studies of protein-protein interactions have provided evidence that E2F1 and its co-operating factor DP1 can complex with p53 both in vitro and in vivo.

Bile salt hydrophobicity controls vesicle secretion rates and transformations in native bile.

After drainage of the bile salt pool, we infused unanesthetized bile fistula prairie dogs (Cynomys ludovicianus) intravenously with taurine-conjugated chenodeoxycholate (TCDC), cholate (TC), ursodeoxycholate (TUDC), and ursocholate (TUC) in concentrations that attained greater than 94% enrichment of biliary bile salts. With decreases in bile salt hydrophobicity, maximum steady state lecithin and to a lesser extent cholesterol secretion rates decreased in the rank order, TCDC greater than TC greater than TUDC greater than TUC. By phase analysis, TCDC-rich and TC-rich biles plotted inside their respective micellar zones, whereas TUDC-rich and TUC-rich biles plotted outside and were so-called "supersaturated" with cholesterol. Quasi-elastic light scattering and electron microscopy, when performed within 30 min of collection, revealed unilamellar vesicles in all biles. By 24 h, vesicles in TCDC-rich and TC-rich biles had dissolved into mixed micelles, whereas vesicles in TUDC-rich biles formed mixed micelles plus multilamellar liquid crystals, and vesicles in TUC-rich biles formed multilamellar liquid crystals exclusively. Because cholesterol/phospholipid molar ratios of multilamellar liquid crystals were less than or equal to 1, cholesterol monohydrate crystals did not form in these biles. We conclude that, despite drastic alterations in bile salt detergency, unilamellar vesicles are the final common pathway for lecithin and cholesterol secretion into bile. During equilibration of bile, the fate of unilamellar vesicles may be micellar, micellar plus liquid crystalline, or liquid crystalline only depending on the detergency (i.e., hydrophobic-hydrophilic balance) of the secreted bile salt.

Outcomes of surgery for colorectal cancer in patients age 80 years and older.

Three hundred patients treated for colorectal cancer during the period 1975-1980 were divided into two groups (less than 80 yr, 236; greater than or equal to 80 yr, 64). No statistically significant differences were seen between the two groups for American Joint Committee on Cancer (AJCC) stage, site, and length of stay. Operative mortality (30 days) was associated with type of treatment (p less than 0.01), stage (p less than 0.05), and age (p less than 0.01) but not with site of cancer. Five-year survival curves excluding 30-day mortalities showed no significant difference between the two age groups. Proportional hazards linear model (multivariate) analysis showed that, whereas 5-yr survival was related to stage (p less than 0.001) and type of operation, patients greater than or equal to 80 did not have a significantly greater risk of death than patients less than 80 yr. Since the age of the patient influences operative morality, but not 5-yr survival, increasing attention needs to be paid to minimizing operative risk by careful preoperative assessment, optimization of underlying cardiac, pulmonary, and nutritional deficiencies, and monitoring numerous physiologic variables during the intraoperative and postoperative period. Resection of cancer should not be limited or denied on the basis of age alone.

Predictive ability of various nutritional variables for mortality in elderly people.

Nutritional indices (percentage ideal body weight [IBW], serum albumin, serum transferrin, total lymphocyte count [TLC] and delayed cutaneous hypersensitivity [DH] response) were assessed in 80 consecutive patients (aged 85-100 y) within 24 h of admission to determine their predictive value for mortality. Nine patients died. Pearson correlation analysis demonstrated that death was significantly (p less than 0.05 to less than 0.01) associated with sepsis, serum albumin less than 30 g/L, TLC less than or equal to 1500 cells/mm3, and percentage IBW less than or equal to 90%. However, when serum albumin was controlled for, logit regression analyses demonstrated that the impact of other nutritional indices on death was insignificant. The effect of serum albumin remained significant (p less than 0.05 to less than 0.01) even when age and physician's diagnosis were held constant. With the logit model, serum albumin greater than or equal to 30 g/L had a sensitivity of 0.33, specificity of 0.99, and overall predictive power of 0.91. Serum albumin is thus the simplest and best single predictor of mortality and can provide early identification of elderly people at increased risk of death.

Possible psychogenic fever of 103.5 degrees F in a patient with borderline personality disorder.

The authors describe a 24-year-old woman with borderline personality disorder and prolonged fever of unknown origin. After an extensive search for a fever source, they noted that her temperature responded to pseudoseizures and to phenobarbital.